Pressure sensors may be implanted into a patient for temporary or chronic use in a body organ or vessel. Implantable pressure sensors are useful for sensing blood pressure in a heart chamber. Traditionally, such pressure sensors had circuitry components in a housing separate from the sensor. This design caused the sensors to be relatively large because of the additional housing and associated interconnects between the sensor and the circuitry. Therefore, greater space was required within the organ or vessel. Further, such sensors have been designed such that they could generally not be manufactured by mass-production techniques.